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Octopus IOG cheap rate charging

Posted: Sat Aug 01, 2026 12:47 pm
by appman999
I used Mode Scheduler to set up Force Charge during the overnight cheap rate period (and occasionally charging the car in that period)
I'm sure that previously this maintained my battery at 100% through that period and the high loads I set up during that period ran straight from the grid.
However recently (maybe a Fox change?) it appears that Force Charge only charges to 100% and then returns to Self Mode which means the high loads come from the battery (I know I could possibly put in more ct clamps to stop this)
I tried running overnight on Backup mode but that doesn't charge the battery only holds its charge which after the evening usage is now about 80%.
Would it be OK to set the minimum SOC in Backup mode to 100% and thereby forcing the charge?

Re: Octopus IOG cheap rate charging

Posted: Sat Aug 01, 2026 5:23 pm
by MaterialBarracuda48
Backup mode is to hold charge, so if you want it to be 100%, then program that in.

If you have LOTS of PV power, and a smallish export limit, then you can set your system to work in 'Feed-in' mode in the daytime, and it will then 'mop' up PV power that is above your export limit. That is to prevent clipping, or generally maximise your export to grid.

Depending on your house load/needs, then you may just run it as 'Self-use' mode during the daytime.


EDIT: Forgot to say, try not to have the battery sit at 100% for too long, not good for the long term health. You could have it set to 'Backup' mode for most of the night at 80% SoC, and for last hour have it top up to 100%?

Re: Octopus IOG cheap rate charging

Posted: Sat Aug 01, 2026 8:36 pm
by appman999
Thanks for that, daytime isn't a problem. I'm able to export all my surplus.

Do you think force charge would hold it at 100% or once achieved revert to my default self use?

Re: Octopus IOG cheap rate charging

Posted: Sun Aug 02, 2026 9:59 am
by daveg
I find this a good explanation of the modes
https://github.com/TonyM1958/HA-FoxESS- ... des#backup

Re: Octopus IOG cheap rate charging

Posted: Sun Aug 02, 2026 10:07 am
by appman999
Thanks for that

Re: Octopus IOG cheap rate charging

Posted: Sun Aug 02, 2026 11:12 am
by daveg
My inverter is still meeting load from grid after it reaches battery charge target until the end of the force charge period. Then it goes to self use.
Possibly because I haven't applied firmware updates for a while.

Re: Octopus IOG cheap rate charging

Posted: Sun Aug 02, 2026 11:19 am
by appman999
Does your battery then maintain the charge target until the end of the force charge period?

Re: Octopus IOG cheap rate charging

Posted: Sun Aug 02, 2026 11:28 am
by daveg
Yes.
But if I go to create a new force charge period the words in the app imply that one will move self use after FCSoC is reached. So I stick with the one I've got.

Re: Octopus IOG cheap rate charging

Posted: Sun Aug 02, 2026 11:37 am
by appman999
I think you're probably right, as they say if it ain't broke ....
My work round is to use Backup for most of the off peak and then a short gentle charge to 100% before 05:30

Re: Octopus IOG cheap rate charging

Posted: Sun Aug 02, 2026 11:54 am
by daveg
I don't know if the situation you're finding is now the intended behaviour or an unintended consequence of a fix for the force discharge problem where it was drawing from the grid (at peak cost rates) when FDSoC battery target was reached before the end of the Force Discharge period.
The next round of firmware and app updates might clarify I guess.

Re: Octopus IOG cheap rate charging

Posted: Tue Aug 04, 2026 8:26 am
by daveg
I am now being offered an inverter firmware upgrade to 1.78/1.59.
I see they are still shown by Will as in testing. As my system is working as I want I'll pass for now.
Those with current problems might think it worth a punt.

Re: Octopus IOG cheap rate charging

Posted: Tue Aug 04, 2026 9:29 am
by daveg
No release notes as usual, but this is what AI thinks it does for force charge (among other things). It may be AI hallucination, or it may accurately reflect Fox intent but reality may differ, as previously. Or it may work!

'The Manager 1.78 / Master 1.59 release is the patch update FoxESS rolled out specifically to resolve the bugs introduced during the 1.76 / 1.57–1.58 rollout.

Fix for the Force Charge / FCSoC Early Fallback
The Problem in 1.76: When the battery reached the Target FCSoC during a scheduled Force Charge slot, the inverter immediately dropped back into Self-Use mode, draining the battery for home loads while still inside the cheap electricity window.
The 1.78/1.59 Fix: Time windows and SoC limits are now decoupled correctly. When the battery hits your FCSoC target, charging stops, but the home load remains on grid power until the scheduled time window actually ends.'

Re: Octopus IOG cheap rate charging

Posted: Tue Aug 04, 2026 9:30 am
by appman999
Thanks for that, I'll seek the update

Re: Octopus IOG cheap rate charging

Posted: Tue Aug 04, 2026 3:11 pm
by daveg
I don't know what the equivalent versions would be for the AC1 series, or if they've been released. The model doesn't seem to appear on Will's firmware sheet.

Re: Octopus IOG cheap rate charging

Posted: Tue Aug 04, 2026 4:50 pm
by appman999
Updated to 1.78/1.59, hopefully resolves force charge issue.

Re: Octopus IOG cheap rate charging

Posted: Tue Aug 04, 2026 5:32 pm
by daveg
I'll be very interested in how it works out.
If it works as expected I might update myself.
I suspect if I keep refusing updates a time will eventually come when my firmware is too old to be compatible withe the current App version.

Re: Octopus IOG cheap rate charging

Posted: Wed Aug 05, 2026 9:28 am
by appman999
Didn't work for me, charged to 100% and then appeared to return to self use!
Trying now to split the force charge into 3 seperate slots so it keeps topping up.

Re: Octopus IOG cheap rate charging

Posted: Wed Aug 05, 2026 9:47 am
by MaterialBarracuda48
When I was on IOG with Home Assistant, it always showed as 'Backup' mode, and was holding 100% until the time ran out.

Have you tried backup work mode yet?

Re: Octopus IOG cheap rate charging

Posted: Wed Aug 05, 2026 9:52 am
by appman999
Yes. Unfortunately it only holds the charge at the level it was, it doesn't increase it to 100%.
I'd need to know when it was at 100%(or near that) before turning on Backup.
I know I could do it in Home Assistant but I'm trying to keep it simple and just use mode scheduler.

Re: Octopus IOG cheap rate charging

Posted: Wed Aug 05, 2026 9:57 am
by MaterialBarracuda48
Can you show image of your work schedule?
As on my KH inverter it does show 'After Charging Cut-off' and there's an option for 'Standby'

It might not exist on your hardware/firmware version is why I was asking.

Re: Octopus IOG cheap rate charging

Posted: Wed Aug 05, 2026 10:10 am
by appman999
The only option I have overall is to set the mode for anything not in a defined slot.

Re: Octopus IOG cheap rate charging

Posted: Wed Aug 05, 2026 10:13 am
by MaterialBarracuda48
It does not exist in the website for me, but does in the App :!:

Added image here for you
Screenshot_20260805_101433_FoxCloud20.png

Re: Octopus IOG cheap rate charging

Posted: Wed Aug 05, 2026 10:34 am
by appman999
👍👍👍
Thanks very much, same here. That solves my problem🤞
Strange the app and web are different? Maybe an update due.

Re: Octopus IOG cheap rate charging

Posted: Wed Aug 05, 2026 10:44 am
by MaterialBarracuda48
appman999 wrote: Wed Aug 05, 2026 10:34 am 👍👍👍
Thanks very much, same here. That solves my problem🤞
Strange the app and web are different? Maybe an update due.
Well, let's test it before we pop champagne :lol:
It has been out of sync before, where website had settings the App didn't.

Best of luck with testing...

Re: Octopus IOG cheap rate charging

Posted: Wed Aug 05, 2026 10:49 am
by appman999
Do you think that came with the latest firmware upgrade 1.78/1.59?